“Hypotheses are nets: only he will catch who casts his net.” —Novalis (1772-1801), trans. F.V.M.T. & U.C.B. (1903), The Disciples at Saïs and Other Fragments https://archive.org/details/disciplesatsais00nova/page/68/mode/2up?q=catch

“Only in opinion consists sweetness, bitterness, cold, color; in truth there is nothing but the atoms and empty space.” –Democritus (c. 460 – .c 370 BC)
trans. R. G. Bury (1935) Against the Logicians. Sextus Empiricus. II. https://www.loebclassics.com/view/sextus_empiricus-against_logicians/1935/pb_LCL291.411.xml

“So primal germs have solid singleness, / Which tightly packed and closely joined cohere / By virtue of their minim particles — / No compound by mere union of the same” – Lucretius (c. 99 – 55 BC) Of the Nature of Things trans. William Ellery Leanard (1916) https://archive.org/details/ofthenatureofthi00lucruoft/page/18/mode/2up

“And perhaps when such attrition stops at or is confined to the smallest quanta, their motion is temporaland their action calorific only; but when their ultimate and highest resolution into truly indivisible atoms is arrived at, light is created.” – Galileo Galilei (1564-1642), The Assayer (1623), trans. Stillman Drake https://archive.org/stream/B-001-001-741/B-001-001-741_djvu.txt

“A vessel full of any pure elastic fluid presents to the imagination a picture like one full of small shot. The globules are all of the same size, but the particles of the fluid differ from those of the shot, in that they are constituted of an exceedingly small central atom of solid matter, which is surrounded by an atmosphere of heat, of great density next the atom, but gradually growing rarer according to some power of the distance ; whereas those of the shot are globules, uniformly hard throughout, and surrounded with atmospheres of heat of no comparative magnitude.” – John Dalton (1766-1844), A New System of Chemical Philosophy, pt. 1 (1808) https://archive.org/details/newsystemofchemi01daltuoft/page/n591/mode/2up?q=atom

“We suppose that the atom consists of a number of corpuscles moving about in a sphere of uniform positive electrification : the problems we have to solve are (1) what would be the structure of such an atom~ i. e. how would the corpuscles arrange themselves in the sphere; and (2) what properties would this structure confer upon the atom.” – J.J. Thomson (1856-1940), “On the structure of the atom” (1904) https://uni-tuebingen.de/fileadmin/Uni_Tuebingen/Fakultaeten/MathePhysik/Institute/IAP/Forschung/MOettel/Geburt_QM/thomson_PhilMag_7_237_1904.pdf

“If the movement discussed here can actually be observed (together with the laws relating to it that one would expect to find), then classical thermodynamics can no longer be looked upon as applicable with precision to bodies even of dimensions distinguishable in a microscope : an exact determination of actual atomic dimensions is then possible.” – Albert Einstein (1879-1955), Investigations on the Theory of the Brownian Movement (1905), trans. A.D. Cowper https://www.mit.edu/~kardar/research/seminars/motility/eins_brownian.pdf

“A simple calculation shows that the atom must be a seat of an intense electric field in order to produce such a large deflexion at a single encounter” – Ernest Rutherford (1871-1937), “The Scattering of α and β particles by Matter and the Structure of the Atom” (1911) https://www.chemteam.info/Chem-History/Rutherford-1911/Rutherford-1911.html

“General evidence indicates that an atom of hydrogen consists simply of a single electron rotating round a positive nucleus of charge e.” ““These calculations strongly suggest that an electron of great velocity in passing through an atom and colliding with the electrons bound will loose energy in distinct finite quanta.” “Further, there may be stationary configurations of a system of n electrons and a nucleus of charge E in which all the electrons are not arranged in a single ring.”““In any molecular system consisting of positive nuclei and electrons in which the nuclei are at rest relatiwe to each other and the electrons move in circular orbits, the angular momentum of every electron round the centre of its orbit will in the permanent state of the system be equal to h/2π, where h is Planck’s constant.”” – Niels Bohr, 1913, “On the Constitution of Atoms and Molecules,” https://www.informationphilosopher.com/solutions/scientists/bohr/Constitution_of_atoms_I.pdf

“The point of view taken here, which was first published in a series of German papers, is rather that material points consist of, or are nothing but, wave-systems.” “- Schrödinger, 1926, “An Undulatory Theory of the Mechanics of Atoms and Molecules,” 1926 https://www.ub.edu/hcub/hfq/sites/default/files/Schr%C3%B6dinger_1926_eng.pdf

“Above all, the uncertainty in our observation does not arise exclusively from the occurrence of discontinuities, but is tied directly to the demand that we ascribe equal validity to the quite different experiments which show up in the corpuscular theory on one hand, and in the wave theory on the other hand.” Werner Heisenberg (1901-1976), The Physical Content of Quantum Kinematics and Mechanics (1927), trans. J.A.W. and W.H.Z. https://www.informationphilosopher.com/solutions/scientists/heisenberg/Heisenberg_Uncertainty.pdf

“These general features agree with what one would expect from the shell model. The high peaks at the doubly magic nuclei are due to the fact that their excitation can only be brought about by removing one nucleon from a closed shell and bringing it into a level which is much higher in energy.” Maria Goeppert Mayer, Elementary Theory of Nuclear Shell Structure, 1955 https://archive.org/details/elementarytheory0000mari_q8f2/page/n7/mode/2up

I found this video very useful for actually building some intuition for why the quantization of light results in a different relationship between spectral radiance and wavelength in the ultraviolet range. Most videos get either hand-wavey or extremely technical about this part. https://www.youtube.com/watch?v=vPW0UYELfOg

“The starting point was the discovery of an element of wholeness, so to speak, in the physical processes, a feature going far beyond the old doctrine of the restricted divisibility of matter. This element is called the universal quantum of action. It was discovered by Max Planck in the first year of this century and came to inaugurate a whole new epoch in physics and natural philosophy.”

  http://www.nhn.ou.edu/assets/doc-or-pdf/Bohr-1957-large.pdf

““According to this picture, the energy of a light wave emitted from a point source is not spread continuously over ever larger volumes, but consists of a finite number of energy quanta that are spatially localized at points of space, move without dividing and are absorbed or generated only as a whole.”” – Albert Einstein, 1905, On a Heuristic Point of View about the Creation and Conversion of Light. https://en.wikisource.org/wiki/Translation:On_a_Heuristic_Point_of_View_about_the_Creation_and_Conversion_of_Light

“Oui, c’est en 1929 que j’ai reçu le prix Nobel de physique pour la découverte de l’aspect ondulatoire des électrons. C’était le résultat de très longues réflexions. En 1905, quand j’avais 13 ans, Monsieur Einstein avait découvert que dans la lumière, il y a non seulement des ondes, comme on le savait depuis longtemps, mais aussi des corpuscules, ce qui lui avait permis d’expliquer l’effet photoélectrique, qui n’était pas explicable jusqu’alors. Et puis j’avais étudié aussi beaucoup la théorie de la relativité. C’est à la suite de toutes ces études que j’ai eu l’idée qu’il fallait étendre à toutes les particules matérielles, et en particulier aux électrons, l’idée que la particule est accompagnée d’une onde.”

“Yes, it was in 1929 that I received the Nobel Prize in Physics for the discovery of the wave nature of electrons. It was the result of a very long period of reflection. In 1905, when I was 13 years old, Mr. Einstein had discovered that in light, there are not only waves, as had been known for a long time, but also corpuscles, which allowed him to explain the photoelectric effect, which was not explainable until then. And then I had also studied the theory of relativity a lot. It was following all these studies that I had the idea that it was necessary to extend to all material particles, and in particular to electrons, the idea that the particle is accompanied by a wave.” – Louis de Broglie

https://www.ina.fr/ina-eclaire-actu/video/afe04002106/monsieur-de-broglie

Transcribed and translated by Gemini

“At the instant when position is determined—therefore, at the moment when the photon is scattered by the electron—the electron undergoes a discontinuous change in momentum.” — Werner Heisenberg, 1927.
“The Physical Content of Quantum Kinematics and Mechanics” https://www.informationphilosopher.com/solutions/scientists/heisenberg/Heisenberg_Uncertainty.pdf

“The behavior of things on a small scale is so fantastic. It’s so wonderfully different, so marvelously different than anything that behaves on a large scale. You say electrons act like waves–no they don’t, exactly. They act like particles–no they don’t, exactly. They act like a kind of a fog around the nucleus–no they don’t, exactly!” – Richard Feynman https://www.youtube.com/watch?v=P1ww1IXRfTA

“We physicists like to look for something that is symmetrical in the world. Many of our deepest truths about nature are expressed by a symmetry that we are able to recognize in a property of nature. Thus we like to see that our laws of motion are exactly the same when viewed through a looking glass, that is, when we have interchanged everything on the right side to the left side. That shows a symmetry in space. We might also look for a symmetry in time, by expecting our laws to work as well when time is reversed; for example, Newton’s laws are the same for the objects in a movie even when the projector runs backward. Still, symmetry can be boring, so after we have recognized a property of nature that is symmetrical, we are utterly delighted to find any small deviation from the rule.” – Robert Rathbun Wilson https://history.fnal.gov/goldenbooks/gb_wilson.html

“And then more recently other symmetries have appeared in physics, a symmetry between proton and neutron. And this is only an approximate symmetry what physicists call a broken symmetry.” – Paul Dirac https://www.youtube.com/watch?v=xJzrU38pGWc&t=243s

First use of “entanglement” by Erwin Schrödinger: “Discussion of Probability Relations between Separated Systems” https://www.informationphilosopher.com/solutions/scientists/schrodinger/Schrodinger-1935.pdf

Title credit to Doğa Kurkcuoglu

“Not to fear rethinking the world is the power of science . . .” —Carlo Rovelli, Helgoland, 2021, trans. Erica Segre and Simon Carnell
Helgoland: Making Sense of the Quantum Revolution. Riverhead Books, 2021 https://www.penguinrandomhouse.com/books/653621/helgoland-by-carlo-rovelli-translated-by-erica-segre-and-simon-carnell/

“The supreme task of the physicist is to arrive at those universal elementary laws from which the cosmos can be built up by pure deduction. There is no logical path to these laws; only intuition, resting on sympathetic understanding of experience, can reach them. . . . The state of mind which enables a man to do work of this kind is akin to that of the religious worshiper or the lover; the daily effort comes from no deliberate intention or program, but straight from the heart.” – Einstein “Principles of Research” trans. Sonja Bargmann, Ideas and Opinions Copyright. 1954, by Crown Publishers. Inc. https://speakola.com/ideas/albert-einstein-principles-of-research-1918

“Das Glück des Forschers besteht nicht darin, eine Wahrheit zu besitzen, sondern die Wahrheit zu erringen. Und in diesem fortschreitend erfolgreichen Suchen nach der Wahrheit, da liegt die eigentliche Befriedigung.”

“The happiness of a researcher consists not in possessing a truth, but in attaining it. And in this progressively successful search for truth lies the real satisfaction.” – Max Planck, Geheimrat Max Planck (film), 1942

transcription and translation by Gemini https://www.youtube.com/watch?v=B9FpAGK8bj8&t=1169s

“My aspiration as a scientist is to learn something all the time, to get closer and closer to understanding of a broader range of phenomena, and one of the things that we’ve learned . . . that questions that once started out as metaphysical questions become within the range of scientific questions—some of them we can even answer.”- Chris Quigg https://www.youtube.com/watch?v=61LFWP1JvsE

“The art of science has been to create concepts, and then to create theories using those concepts that correspond to reality. . . . If it is at all plausible that the concepts of physics themselves have at least in some degree been arbitrary creations of man, rather than being “revealed truth”, or being something that was just inherently obvious to anyone, then it might also be plausible to go on and to inquire if all knowledge of physics has not in large measure been created by the mind of man . . . The difference is that physics must constantly, step-by-step, be consistent with the world of reality as determined by experiment.” – Robert Wilson https://history.fnal.gov/goldenbooks/gb_wilson.html

“I believe that one of the greatest mistakes made by human beings is to want certainties when trying to understand something. The search for knowledge is not nourished by certainty: it is nourished by a radical absence of certainty. Thanks to the acute awareness of our ignorance, we are open to doubt and can continue to learn and to learn better. This has always been the strength of scientific thinking—thinking born of curiosity, revolt, change. There is no cardinal or final fixed point, philosophical or methodological, with which to anchor the adventure of knowledge.” —Carlo Rovelli, Helgoland, 2021, trans. Erica Segre and Simon Carnell
Helgoland: Making Sense of the Quantum Revolution. Riverhead Books, 2021 https://www.penguinrandomhouse.com/books/653621/helgoland-by-carlo-rovelli-translated-by-erica-segre-and-simon-carnell/

“So we’ll continue to peel away at the more hidden layers of truth, and, and again, we believe that we’ll find a more complete and elegant theory. But as is the case with the onion, we must wonder whether there will ever emerge an ultimate layer where the peeling must stop.” – Young-Kee Kim, https://www.youtube.com/watch?v=Fn87tmuYb1U&t=3s

“”The final answer eludes us, and it’s going to take a lot of hard work and clever experiments to get us to the end of the road. This isn’t a project that will be solved in months or years; indeed, it will take lifetimes. For those who want to know the answer, it’s important to remember an inescapable truth: the only way to complete a journey is to keep taking steps. And we scientists have started walking.” – Don Lincoln

“I think nature’s imagination is so much greater than man’s, she’s never going to let us relax!” Richard Feynman https://www.youtube.com/watch?v=P1ww1IXRfTA